Objective—To characterize ocular findings in hypertensive dogs, determine prevalence of hypertension in dogs with ocular disease suggestive of hypertension, and examine possible relationships between degree of hypertension and ocular disease.
Design—Retrospective case series.
Animals—65 dogs initially referred for blood pressure measurement (n = 22), ophthalmic examination (25), or both (18).
Procedures—Medical records were reviewed to identify dogs examined at the teaching hospital that underwent a complete ophthalmic examination and blood pressure measurement within a 24-hour period between January 1, 2005, and December 31, 2007. Signalment, history, blood pressure measurements, ophthalmic examination findings, and any vasoactive drug treatments were recorded. Ocular lesions considered likely to be associated with systemic hypertension included retinal hemorrhage, retinal detachment, hyphema, tortuous vessels, and subretinal edema.
Results—Of the 65 dogs, 42 were hypertensive (systolic blood pressure ≥ 160 mm Hg) and 23 were normotensive. Sixty-two percent (26/42) of hypertensive dogs had ≥ 1 type of ocular lesion identified. Retinal hemorrhage was the most common ocular lesion in hypertensive dogs (17/42 [40%]). The presence of ≥ 1 type of ocular lesion had moderate sensitivity and specificity of 62% and 61 %, respectively, for identification of hypertension. Fifteen of the 25 (60%) dogs referred for blood pressure measurement after initial ophthalmic examination were found to be hypertensive.
Conclusions and Clinical Relevance—Ocular lesions are common in dogs with systemic hypertension. Dogs with hypertension or diseases associated with hypertension should be monitored carefully for evidence of ocular target organ damage, and hypertension should be systematically ruled out in dogs with characteristic ocular lesions.
To investigate the usefulness of radiographic measures of the left atrium and ventricle as surrogates for echocardiographic criteria in identifying dogs with stage B2 preclinical myxomatous mitral valve disease (MMVD).
56 client-owned dogs with preclinical mitral regurgitation attributed to MMVD examined between April 19, 2016, and November 22, 2017.
Medical records were retrospectively searched, and data collected included age, body weight, heart murmur grade, and echocardiographic and radiographic measurements. Dogs were grouped according to whether they did (case dogs) or did not (control dogs) meet echocardiographic criteria used to identify dogs with stage B2 MMVD. Measurements for lateral thoracic radiographic variables normalized to vertebral body units (VBUs) were obtained, and results were analyzed to identify variables that could best discriminate between case and control dogs.
Three radiographic variables of left atrial size (vertebral left atrial size [VLAS], left atrial width, and the combined variable of VLAS + left atrial width) most accurately distinguished control dogs from case dogs, and the VLAS was the simplest and fastest to perform in a clinical setting. The optimal cutoff for VLAS was 2.5 VBUs (sensitivity, 70%; specificity, 84%; and likelihood ratio, 4.38), with VLAS ≥ 2.5 VBUs for case dogs. The maximum specificity cutoff for VLAS was 3.0 VBUs (sensitivity, 40%; specificity, 96%; and likelihood ratio, 10.0), with VLAS ≥ 3.0 VBUs for case dogs.
CONCLUSIONS AND CLINICAL RELEVANCE
Results indicated that when echocardiography is unavailable, radiographic VLAS ≥ 3 VBUs could be used with minimal risk of false-positive diagnosis of stage B2 MMVD in dogs.
Objective—To determine the effect of endurance
training on QRS duration, QRS-wave amplitude, and
Animals—100 sled dogs in Alaska.
Procedure—Dogs were examined in early
September (before training) and late March (after
training). During the interim, dogs trained by pulling a
sled with a musher (mean, 20 km/d). Standard and
signal-averaged ECG were obtained before and after
Results—Endurance training significantly increased
mean QRS duration by 4.4 milliseconds for standard
ECG (mean ± SEM; 62.3 ± 0.7 to 66.7 ± 0.6 milliseconds)
and 4.3 milliseconds for signal-averaged ECG
(51.5 ± 0.7 to 55.8 ± 0.6 milliseconds) without changing
body weight. Increase in QRS duration corresponded
to a calculated increase in heart weight
(standard ECG, 23%; signal-averaged ECG, 27%).
Signal-averaged QRS duration was correlated with
echocardiographically determined left ventricular diastolic
diameter for the X orthogonal lead (r = +0.41), Y
orthogonal lead (r = +0.33), and vector (r = +0.35).
Training also increased QT interval (234 ± 2 to
249 ± 2 milliseconds) and R-wave amplitude in leads
II and rV2, increased peak-to-peak voltage and S-wave
amplitude in the Y orthogonal lead, and decreased Q-wave
amplitude in the Y orthogonal lead.
Conclusions and Clinical Relevance—Electrocardiographic
changes reflected physiologic cardiac
hypertrophy in these canine athletes in response to
repetitive endurance exercise. The QRS duration
increases in response to endurance exercise training
and, therefore, may be of use in predicting performance
in endurance activities. (Am J Vet Res 2000;61:582–588)
Objective—To determine whether plasma cardiac troponin I (cTnl) concentrations can be used to identify cardiac involvement in dogs with hemangiosarcoma, exclude cardiac hemangiosarcoma in dogs with noncardiac hemangiosarcoma, and identify cardiac hemangiosarcoma in dogs with pericardial effusion.
Animals—57 dogs (18 with confirmed [5 dogs] or suspected  cardiac hemangiosarcoma, 14 with confirmed hemangiosarcoma involving sites other than the heart [noncardiac hemangiosarcoma], 10 with pericardial effusion not caused by hemangiosarcoma, and 15 with noncardiac nonhemangiosarcoma neoplasms).
Procedures—Plasma cTnl concentration was measured, and thoracic radiography, abdominal ultrasonography, and echocardiography were performed in each dog. The cTnl concentration was compared among groups.
Results—Median plasma cTnl concentration in dogs with cardiac hemangiosarcoma was significantly higher than the concentration in each of the other groups. A plasma cTnl concentration > 0.25 ng/mL could be used to identify cardiac involvement in dogs with hemangiosarcoma at any site (sensitivity, 78%; specificity, 71 %). A plasma cTnl concentration > 0.25 ng/mL could be used to identify cardiac hemangiosarcoma in dogs with pericardia effusion (sensitivity, 81%; specificity, 100%).
Conclusions and Clinical Relevance—The median plasma cTnl concentration was higher in dogs with cardiac hemangiosarcoma, compared with the median concentration in dogs with hemangiosarcoma at other sites, dogs with other neoplasms, and dogs with pericardial effusion not caused by hemangiosarcoma. The plasma cTnl concentration may be used to identify cardiac involvement in dogs with hemangiosarcoma and to identify cardiac hemangiosarcoma in dogs with pericardial effusion. (J Am Vet Med Assoc 2010;237:806–811)